Default font question

["Andrew E. Makeev" <andrew solvo ru>]

Hi

Could someone explain, please, how should I to determine default font 
name for widget where it's applicable (label, textview, etc)?
I have used these methods:

1. Using GtkStyle: Gtk::Label ().get_style ()->get_font ().to_string () 
- returned "Sans 10"
2. Using GtkRcStyle: Gtk::Label ().get_modifier_style ()->get_font () - 
returned Pango::FontDescription with gobj() == 0 (no font specified)

It's fine for Linux, but wrong on Win32 system, because it uses theme 
font = "Thahoma 8".
Is there a right way to get theme default font name? (An example will be 
much better than lotsa theory :) )

Thanks in advance,
-andrew